by Jamie Bullen and political editor Paul Francis

A furious headteacher has threatened to sue the GCSE exam board following claims English results had been deliberately downgraded.

Simon Murphy, principal at Chaucer Technology College, slammed the AQA exam board as a ‘disgrace’ claiming English GCSE results were made unfairly harder in this year’s examinations.

He claims many students who recorded D grades in the subject would have received B if they sat the test six months ago

He said an investigation had been launched along with other schools across the city and legal action has not been ruled out.

Despite the controversy, his school recorded their best ever exam results, including English and maths combined scores.

He said: “This is a fiasco of significant proportions. We will be following this up with legal action if necessary.

• The highs and lows of this year's GCSE results

• What to do if your exams aren't what you expected

“I do not believe that this is ethically right for students or the teachers who have done everything they could and should, yet do not obtain the grade that, had they taken the examination sixth months earlier, they would have achieved.

"If our students had taken the examination in January, they would have achieved a grade B now, with the same standard examination, the best they can achieve is a grade D. This is disgraceful.”

Other headteachers across the county echoed Mr Murphy’s claims calling for a full investigation into the marking.

"this is a fiasco of significant proportions. we will be following this up with legal action if necessary" – simon murphy, principal, chaucer technology college

Ian Bauckham, head of the Bennett Memorial School in Tunbridge Wells, said: “I have spoken with many heads up and down the country over the past 24 hours, and all have agreed that English results show a marked fall in comparison with other subjects.

“This will need investigation, and it is by no means clear what has happened exactly.”

Sally Lees, the headteacher of Tenterden's Homewood School, said: "We did not feel the English language results were accurate - it is a national problem."

Cllr Mike Whiting, KCC cabinet member for schools, said he was aware there was an issue with grades in the subject from the schools he had visited.

“I do not know what has happened but it does appear that some schools are reporting that while grades in some subjects have held up or improved in English they have gone down in a way they did not expect, and we will need to look at it.”